Fishes, amphibians (salamander), reptiles (gecko and chameleon), birds (canary) and some mammals (rat and mouse) use UV (ultraviolet) vision for such basic behaviors as foraging, mate selection and communications, etc. (Yokoyama 2000). At the first year (H14;2002), it was clarified that the retina of Pagothenia borchgrevinki and Trematomus bernacchii was examined, and they had UV cone by which they took part in the ultraviolet vision in the fundus retina (Miyazaki et al.2002). Moreover, it has been understood that Kaiwari (carangid fish, Kaiwarinus equula) with tapetum doesn't have UV vision (Takei & Somiya 2002). In next fiscal year (H15;2003), It has been implied that the archerfish (Toxotes jaculatrix) with air vision don't have UV cone that takes part in the UV vision. In final fiscal year (H16;2004), it has been found that the four-eyed fish (Anableps anableps) with both air and under water vision have the UV vision. Moreover, it was found that the fish use the horizontal visual streak in both air and water visions and two areas were observed in the streak. However, the exact function of the four eyed-fish UV vision was not able to be clarified. The exact function of the four eyed-fish UV vision will be the subject of future research.